Purifying gasolene fractions containing aromatic hydrocarbons.



FREDERICK O. RUFF, OF LOS ANGELES, CALIFORNIA, ASSIG-NOIR TO IBY-PRODUOTS MANU- FACTURING- COMPANY, OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF CALIFORNIA.

runlrxme GA-SOIJENE r nnc'rxons CONTAINING Annmarie HYnRoc AnBoNs.

No Drawing.

To all whom it may concern:

Be it known that I, FREDERICK O. RUFF, a subject of the Emperor of Germany, residing at'Los 'Angeles, inlthe county of Los Angeles and State of California, have invented new and useful Improvements in Purifying Gasolene Fractions Containing Aromatic Hydrocarbons, of which the following is a specification.

In refiningmineral oils, sulfuric acid of suflicient strength applied in'suflicient quantity and at a s ciently high temperature, is used for the purpose of eliminating unsaturated hydrocarbons. For example, in refining kerosene, fuming-sulfuric acid is successfully used. Some mineral oils contain in their gasolene fraction such a proportion of toluene as to render it profitable to recover the same therefrom. This toluene can, by a nitrating process, be successfully recovered as a nitrated compound. But in saturated aliphatic hydrocarbons forin so.

this case, likewise, in order to'carry out the nitrating process successfully and economically, the unsaturated aliphatic hydrocarbons have to'be first removed. .But the unsmall a proportion of the entire gasolenetoluene fraction and the difference in their densities is so great that a large. amount of acid has to be used to insure a thorough mixture by agitation; If the acid used be fuming sulfuric acid, it will be found that a large percentage of the toluene has been eliminated, slnce' toluene, as well as unsaturated hydrocarbons, is soluble in fuming sulfuric acid. It might have been supposedthat this difliculty'would be overcome by employing weak sulfuric acid, which will dissolve the unsaturated hydrocarbons without dissolving also aart of the toluene, but the weak sulfuric acid will not attack the unsaturated hydrocarbons readily enough to secure satisfactory results." 7

By adding a small amount of nitric acid, fromO.25% to 0.75%, to sulfuric acid. (64

to 66 Baum) I have found, however, that I I can efiect the almost complete. elimination of the unsaturated hydrocarbons, while at the, same time only in refining.

Specification ofLetters Patent.

traces of toluene are lost Patented Apr. f6, 1918.

v Application filed January 15, 1917. Serial No. 142,540.

In nitrating the gasolene-toluene fraction refined by the above method, a smaller quantity of a mixture ofsulfurio and nitric acids has to be applied, and the resulting tri-nitro- The expense is small because the'unsaturated hydrocarbons have been eliminated by a comparatively eak sulfuric acid which is comparatively cheap and contains only a small amount of nitric acid. The nitration itself is .a safe operation because the unsaturated hydrocarbons have been eliminated. These unsaturated hydrocarbons have a great affinity for nitric acid, and tend to cause violent instantaneous reactions.

I claim 1. The process of removing unsaturated aliphatic hydrocarbons, from gasolene fractions containing an aromatic hydrocarbon, which consists 'in adding to the gasolene fraction sulfuric acid containing nitric acid to the extent of not more than one per cent. of the sulfuric acid.

2. The process of removing unsaturated aliphatic hydrocarbons from gasolene fractions containing an aromatic hydrocarbon, which consists in adding to the gasolene fraction sulfuric acid containing nitric acid in an amount insuiflcient to materially attack the aromatic hydrocarbon'contained in the -"gasolene fraction.

.taining anaromatic hydrocarbon, which consists in adding to the light oil sulfuric acid containing nitric acidin the extent of not more thanone per cent, of'the sulfuric acid. e

4. The rocess of removing unsaturated aliphatic ydrocarbons from, light. oil containing an aromatic hydrocarbon, which con-.

si'sts in adding to theflight oil sulfuric acid containing nitric'acid in an amount insufiidrecarhon contained the light oil.

- rei'iimniexonurr.

cient to materially attack the aromatic hy-, 

